Heat seal device

ABSTRACT

A heat-sealing device moves a tube-shaped packaging material through operation of a seal jaw and counter jaw under the liquid surface of liquid food, and heat-seals a seal zone containing a cutting predetermined zone in the tube transverse direction. The tube-shaped packaging material is formed from the packaging material web, and is filled up with liquid food. The operation surface of the seal jaw facing the seal zone has a substantially flat surface. The heat-sealing device has a removal/mixture mechanism on the operation surface of the counter jaw. The removal/mixture mechanism removes seal prevention impurity from this seal zone and/or mixes the impurity with the melting/softening packaging material in this seal zone. Thus, even if the packaging laminated material is covered with an oxide, residual substances, or impurities, the heat-sealing device reduces the bad influence of the seal prevention impurity.

FIELD OF THE INVENTION

This invention relates to a device which heat-seals tube shapedpackaging material fabricated from a packaging material web in thetransverse direction, and a filling machine utilizing this heat-sealingdevice to manufacture a packaging container filled with fluid food.

BACKGROUND OF THE INVENTION

A filled packaging container used for milk, fruits drink, etc. isgenerally made from laminated packaging material. The packaging materialhas a comparatively rigid main supporting layer covered with thin layersof plastic materials. This material can also contain materials such asaluminum foil. The common feature of this type of packaging laminatedmaterial is that the thermoplastic material (usually polyethylene) layerprovided on the outside and inside of the laminated material is used toform a seal in a liquid tight state with heat and pressure. In order fora seal to have a desired strength and a desired liquid tightperformance, both thermoplastic layers that are to be sealed should beclean, and should not include impurities. With a clean layer, sufficientmelting of each thermoplastic layer can be obtained and, as a result,the optimum seal can be achieved by strong high sealing performance.Since impurities of the thin oxide formed on the packaging laminatedmaterial during the extrusion steps of thermoplastic layers usuallyexist in the thermoplastic layer, a perfect melting between thethermoplastic layers is occasionally prevented. Therefore, a seal cannotacquire the necessary strength and sealing performance. Moreover, whensealing packaging materials under liquid food, impurities associatedwith residual substances of the contents (liquid food) which hinders thesealing further may also be generated or present on the surface of thethermoplastic layer. This is a problem peculiar to the packaging fillingsystem in which sealing of the laminated material is performed under theliquid surface of the liquid food. That is, in this packaging fillingsystem, the content food must be first pushed out from the crevicebetween the surfaces of the thermoplastic materials before sealing.

However, as a practical matter, a very small quantity of residualsubstance remains, without the content food being completely squeezedout, and this residual substance weakens the seal.

SUMMARY OF THE INVENTION

The invention involves a device which can heat-seal the above-mentionedpackaging laminated material so that all the above-mentioned problemsmay be avoided, and thereby provide optimum seal performance. Theinvention also provides a device which heat-seals the packaginglaminated material to avoid the bad influence of seal preventionimpurities as much as possible, while making an optimum seal possible,even if the packaging laminated material is covered with an oxide, theresidual substance of the packaging content, or impurities.

The heat-sealing device heat-seals a tube shaped packaging material inthe transverse direction under the surface of the liquid food. Thetube-shaped packaging material is packaging material formed into thetube shape from a packaging material web, with the liquid food beingfilled up in this tube. The heat-sealing device pushes this tube fromits outside by the seal jaw and the counter jaw, and heat-seals the tubein the transverse direction of the tube. The device heat-seals the sealzone of the packaging material containing a cutting predetermined zoneunder the surface of the liquid food. The operation surface of the sealjaw in contact with the seal zone has a substantially flat surface. Theoperation surface of the counter jaw includes a removal/mixture means.The removal/mixture means removes from the seal zone seal preventionimpurity which may remain in the tube, and/or mixes the impurity withthe melted or softened packaging material in the seal zone.

In a preferred form of this invention, the removal/mixture means may bea slope provided in the operation surface of the counter jaw. The slopemay be in the form of a chevron-shaped operation surface of the counterjaw. In another preferred form of this invention, the removal/mixturemeans can be ridges continuously or discontinuously provided in theoperation surface of the counter jaw. An inductor for forming a sealzone by high frequency induction heating may be arranged in the sealjaw, and the packaging material may comprise a metal thin layer and athermoplastic material innermost layer.

In another preferred embodiment of this invention, a horn for forming aseal zone by ultrasonic heating may be arranged in the seal jaw, and thepackaging material may comprise at least a thermoplastic materialinnermost layer. In another version of this invention, anelectrical-resistor for forming a seal zone by heating is provided inthe seal jaw, and the packaging material may have at least athermoplastic material innermost layer.

The filling machine of this invention forms a packaging material webinto a tube shape, fills up liquid food in the tube, and heat-seals andcuts the tube shape packaging material in the transverse direction. Thefilling machine of this invention utilizes the heat-sealing devicementioned above.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a cross-sectional view showing the structure and operation ofthe heat-sealing device according to a first example of this invention;

FIG. 2 is a sectional view of the packaging material used for theheat-sealing device of this invention;

FIG. 3 is an outline figure showing the structure and operation of thefilling machine equipped with the heat-sealing device of this invention;

FIG. 4 is a cross-sectional view showing the structure and operation ofthe heat-sealing device according to a second example of this invention;

FIG. 5 is a cross-sectional view showing the structure and operation ofthe heat-sealing device according to a third example of this invention;

FIG. 6 is a cross-sectional view showing the structure and operation ofthe heat-sealing device according to a fourth example of this invention;

FIG. 7 is a cross-sectional view showing the structure of the counterjaw of the heat-sealing device according to a fifth example of thisinvention; and

FIG. 8 is a cross-sectional view showing the structure of the counterjaw of the heat-sealing device according to a sixth example of thisinvention.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, although the examples about the heat-sealing device accordingto this invention are described based on the drawings, this invention isnot limited to the examples indicated by these drawings. The outline ofan example of the filling machine equipped with the heat-sealing deviceof this invention is shown in FIG. 3. The filling machine shown in thisexample is operated as follows. From a roll, a filling machine unwindsthe packaging material web 1, which comprises a thermoplastic materiallayer as an innermost layer, and conveys the web to the inside of thefilling machine with rollers. The filling machine seals the strip tape 2to the end of the packaging material web through operation of a striptape applicator 3, and sterilizes the packaging material web by passingit through the inside of the sterilization agent bath 4. The fillingmachine removes the sterilization agent with an air-knife 5, and formsthe web into a tubular shape with forming rollers 6. The tube is filledup with liquid food from a filling pipe 7 extending into the tube, andis sealed by a longitudinal seal element 8 in the longitudinal directionof the tube. To advance the tube below by a length equivalent to onepackaging container, the tube is pushed by seal jaws 10 and counter jaws11 forming the heat-sealing device of this invention, and the fillingmachine heat-seals the tube in the transverse direction, andcontinuously forms pillow-shaped packaging containers 12 simultaneously.Then, a predetermined zone of the seal zone of the pillow-shapedpackaging container is cut with a knife to separate each packagingcontainer 13, and the flaps of the upper and lower sides of theseparated container are folded to form the packaging container 11 havingthe final shape with a final holder 14.

An example of the packaging material 1 which can be used in thisinvention is shown in FIG. 2. This packaging material has theillustrated layer structure, and consists of a thermoplastic materiallayer 31 forming an outermost layer, a paper layer 32, a metal layer 33forming an oxygen barrier layer, and a thermoplastic material layer 34forming an innermost layer.

The packaging material used in this invention is not limited to theabove-mentioned example, but various packaging material can be used. Forexample, packaging laminates can be used that contain low-densitypolyethylene (LDPE)/printing ink layer/paper (fibrous) substratelayer/LDPE/aluminum foil/LDPE/LDPE, LDPE/printing ink layer/papersubstrate layer/LDPE/LDPE, printing ink layer/LDPE/paper substratelayer/LDPE/LDPE, and LDPE/a printing ink layer/paper substratelayer/LDPE/aluminum/polyester (PET).

Moreover, the ethylene alpha olefin copolymer (the so-called metallocenePE) which polymerized using the single site catalyst can also be used asthe innermost layer or/and outermost layer in addition to the LDPEmentioned above.

Furthermore, the vapor deposited layer of an inorganic oxide can also beused as a practical substitute for the metal layer (aluminum foil) asthe above-mentioned oxygen barrier layer.

FIG. 1 shows the seal device of this invention in cross-section with theheat-healed packaging material 1. The main part of the seal jaw 10 ismade from a non-conductive material, and contains the cylindricalinductor 101 of a conductive material, for example, copper.

The inductor 101 is located in the center of the main part forming theoperation surface 102 of the seal jaw 10. The formed operation surfaceis a substantially flat surface. This inductor 101 is arranged to formthe seal zone by high frequency induction heating. The packagingmaterial in this case is a laminate which comprises the thin metal layerand the thermoplastic material innermost layer. In this high frequencyinduction heating, a magnetic field occurs around the coil which isconnected to a high frequency power supply. An eddy current arises inthe metal foil of the coil circumference, and Joule heat is generated bythis eddy current and the resistance of the metal foil layer. Thegenerated Joule heat is transmitted to the thermoplastic materialinnermost layer which faces the metal foil layer, and melts thisthermoplastic material layer. In this example, an inductor 101corresponds to a part of coil of the above-mentioned high frequencyinduction heating. Other portions (not shown) of the coil can bearranged at the reverse side of an inductor 101 or to the exterior ofthe seal jaw 10, etc. In this invention, the operation surface 102 ofthe seal jaw 10 facing the seal zone 20 comprises a substantially flatsurface. The operation surface 111 of the counter jaw 11 possess aremoval/mixture means.

The removal/mixture means removes seal prevention impurity from the sealzone 20, and mixes the impurity with the melted or softened(melted/softened) packaging material in the seal zone 20. In the case ofthis example, removal/mixture means is the ridge 111 continuously ordiscontinuously provided in the operation surface 112 of this counterjaw. The ridge 111 which projects from the operation surface 112 isprovided in the counter jaw 11. The cross-sectional shape of this ridge111 is mostly rectangular. The height of the ridge is 0.2 to 0.8 timesthe thickness of laminated material, preferably 0.5 times. The width isalmost equal to the width of packaging laminated material. The ridge isnot limited to this example, for example it can include a ridge with around top, a ridge having a trapezoidal cross-section, etc.

The operation surface 102 of the seal jaw 10 contains the central zonewhich heats the laminated material 1. The counter jaw 11 includes theridge 111 and the adjoining zones of the ridge. To enable high frequencywelding of the laminated material 1 containing aluminum foil, the highfrequency power supply is connected with an inductor 101, which heatsthe laminated material. When sealing together packaging laminatedmaterial which does not contain aluminum foil (metal layer 33) or otherconductive layers, the laminated material heating zone may consist of,for example, resistance material. The seal device of this invention maymodify this by various methods within the limits of the concept of thisinvention, in order to fulfill the necessary condition of sealingdifferent packaging containers and materials. In this example, the tubeof packaging material is sealed in the transverse direction to form aseal zone, and the seal zone is cut by cutting a predetermined zone 21in the seal zone. A knife (or a certain other suitable cutting devices)operates in the predetermined zone 21. Moreover, in this example, theeddy current by the oscillating magnetic field is induced in thealuminum (metal) layer 33 of the packaging laminated material 1. Thealuminum (metal) layer 33 is heated ro a temperature higher than themelting point of the adjoining thermoplastic layer in the zonecorresponding to the surface of the inductor 101. The generated heat isdirectly transmitted to the thermoplastic layers 34 and 34 locatedbetween the aluminum layers 33 and 33, and melts the thermoplastic layerwhich is changed to a fluid. By virtue of the high pressure(approximately 100 kg/cm²) at which the ridge 111 pushes the packaginglaminated material, the melted thermoplastic material runs and flows tothe zones 20 and 20 from the high-pressure zone 21 of the seal zone. Thethermoplastic layers 34 and 34 which are counter to each other andlocated in the zone outside the seal zones 20 and 20 maintain a solidstate, and are pushed, countering to each other. Without flowing outoutside further, the melted thermoplastic material stops in the zoneshown by reference number 20 in the seal zone, and forms thehigh-pressure zone 21 and the accumulation zones 20 and 20. The twolayers are mixed and sealed to each other in an accumulation portion(zones 20 and 20).

The excess of the plastic that is well mixed at the accumulationportions (zones) 20 and 20 formed in the seal zone is included, and aseal of practically sufficient strength is obtained between the twolayers.

Since the flow by the high pressure is very quick, the mixture ofsufficient plastic material from between the two layers is guaranteed bythe turbulent flow generated in the flowing plastic material.

Therefore, residual substances of the oxide and the liquid food contentexisting in the surface is effectively mixed within the plastic, and afilm of impurities which might adversely affect the strength of the sealdoes not remain.

The seal device of this invention can be modified by various methodswithin the limits of the concept of this invention in order to fulfillthe necessary condition of the seals of packaging containers.

Although the material forming the ridge in the above-mentioned exampleis hard in order to resist deformation associated with the pressureduring the sealing step, the ridge may be made of a deformable elasticmaterial. In this case, although the same seal zones 20 (accumulationportion) as above cannot be significantly formed between laminatedpackaging materials, a higher pressure can be made from a ridge portion.The seal prevention impurity which may remain in the seal zone isremoved from the seal zone, and in the seal zone, melted or softenedpackaging material can be mixed.

FIG. 4 illustrates a second example showing the seal steps at the timeof sealing two packaging laminated materials 1 and 1 through use thedevice of this invention. Two packaging laminated materials 1 and 1 (ortwo facing portions of the same folded-up packaging laminated material)are sealed, particularly the thermoplastic layers of those innermostlayers. The counter jaw 11 and the seal jaw 10 push together thepackaging laminated materials. This seal jaw 10 has a flat operationsurface 102 like the seal jaw shown in FIG. 1. On the other hand, theoperation surface 112 on the counter jaw 11 which faces the packaginglaminated material 1 is sloped so that the cross-sectional shape of theoperation surface 112 is chevron-shaped. During pressing of thepackaging laminated materials 1 and 1 by the seal jaw 10 and the counterjaw 11, this sloping operation surface 112 removes the seal preventionimpurity, which may remain in the seal zone, from this seal zone, andthe sloping surface mixes the impurity with the packaging material thatis melted or softened in the seal zone. Although the mechanism is notnecessarily clear, since the operation surface is inclined, the power ofthe pressure of packaging laminated material inclines, and wheninnermost thermoplastic material is still in a solid state, a contentresidual substance is pushed out by innermost thermoplastic materialfrom the seal zone. The surface oxide and the content residual substanceare pushed out from the seal zone in the softening/melting stage of theinnermost thermoplastic material, and are mixed with the thermoplasticmaterial. In addition, the scope of the present invention is not limitedto this mechanism. As shown in the right-hand portion of FIG. 4, twopackaging laminated materials are sealed by pressure and heating, theseal zones 20 and 20 containing a cutting predetermined zone are formed,and, subsequently, a knife etc. cuts the cutting predetermined zone 21.

FIG. 5 illustrates a third example of the device of this invention forsealing two packaging laminated materials 1 and 1. The thermoplasticinnermost layers of two packaging laminated materials 1 and 1 (or twoportions of the same folded-up packaging laminated material) arepositioned counter to each other in order to be sealed. The packaginglaminated materials are pushed together by the seal jaw 10 and thecounter jaw 11. The horn for forming a seal zone by ultrasonic heatingis arranged in the seal jaw 10, and the seal jaw 10 has the flatoperation surface 102.

On the other hand, the operation surface 112 provided on the counter jaw11 which faces the packaging laminated materials 1 and 1. This operationsurface 112 is sloped to possess a chevron-shaped cross-section. Whenthis sloped surface presses two packaging laminated material 1 and 1 bythe seal jaw 10 and the counter jaw 11, the seal prevention impuritywhich may remain in a seal zone is removed from the seal zone, and themelting/softening packaging material of the seal zone is mixed with theimpurity. Since the operation surface is inclined, the pressure powerapplied to the packaging laminated material is inclined, and when theinnermost thermoplastic material is still in a solid state, a contentresidual substance is pushed out from the seal zone by the solidinnermost layer. In the softening/melting stage of the innermostthermoplastic material, a surface oxide and a content residual substanceare mixed with the softening/melting thermoplastic material, and arepushed out from the seal zone.

As shown in the right-hand side of FIG. 5, two packaging laminatedmaterials are sealed by pressure and heating, the seal zones 20 and 20containing a cutting predetermined zone are formed, and, subsequently aknife, etc., cuts the cutting predetermined zone 21.

FIG. 6 illustrates a fourth example of the sealing device of theinvention for sealing the packaging laminated materials 1 and 1. Thethermoplastic innermost layers of the two packaging laminated materials1 and 1 (or two portions of the same folded-up packaging laminatedmaterial) that are to be sealed are positioned counter to each other.The packaging laminated materials are pushed by the seal jaw 10 and thecounter jaw 11.

The resistance 101 which forms a seal zone 10 by conduction heating isarranged in the seal jaw, and the seal jaw 10 has a flat operationsurface 102. The operation surface 112 which is positioned counter tothe packaging laminated material 1 is provided in the counter jaw 11.This operation surface possesses a cross-section having a slopingstraight line shape from one end of the surface to the other as shown inFIG. 6. When the sloped surface pushes the packaging laminated materials1 and 1 by the seal jaw 10 and the counter jaw 11, the seal preventionimpurity which may remain in the seal zone is removed from this sealzone, and the melting/softening packaging material of the seal zone ismixed with the impurity. Since the operation surface is inclined, thepressure power applied to the packaging laminated material is inclined,and when innermost thermoplastic material is still in a solid state, acontent residual substance is pushed out by the solid innermost layerfrom the seal zone. In the softening/melting stage of innermostthermoplastic material, surface oxide and content residual substance aremixed with the softening/melting thermoplastic material, and/or arepushed out from the seal zone. In addition, the invention is not limitedto this mechanism.

As shown in the right-hand side of FIG. 6, the packaging laminatedmaterial is sealed by pressure and heating, the seal zones 20 and 20containing a cutting predetermined zone are formed, and, subsequentlythe zone is cut by the knife, etc., in the cutting predetermined zone21.

FIG. 7 illustrates a fifth example of the device of the invention whichrepresents a modification of the first example shown in FIG. 1. In thefirst example, the counter jaw has one ridge, whereas in the firthexample shown in FIG. 5 the counter jaw 11 has two ridges 111, 111 atthe operation surface 112. Since the fifth example has two ridges, athird accumulation portion is formed between the two ridges 111, 111. Inthis accumulation portion, the seal prevention impurity is mixed withmelting/softening thermoplastic material, and the accumulation portioninhibits seal prevention.

With the formation of this third accumulation portion, the sealintensity is strengthened, the removal distance of a seal preventionimpurity is shortened, and a quicker seal is made possible.

FIG. 8 illustrates a sixth example of the device of the presentinvention which represents a modification of the second example shown inFIG. 4. In the second example the cross-section of the operation surfacepossesses a single chevron-shaped element, whereas in this sixthexample, the counter jaw 11 has two chevron-shaped elements at theoperation surface 112. The sixth example is the same as the secondexample in general. Since the sixth example has two chevron-shapedelements, the mixed portion (not shown) of a thermoplastic material isformed between these two chevron-shaped elements. In this mixed portion,seal prevention impurity is mixed with melting/softening thermoplasticmaterial, and the mixed portion avoids seal prevention. Like theformation of the third accumulation portion mentioned above inconnection with FIG. 5, by the formation of the mixed portion, sealintensity is strengthened, removal/move distance of a seal preventionimpurity is shortened, and a quicker seal is made possible.

Based on the above-described embodiments of the present invention, thefollowing advantages are shown by the seal device and the fillingmachine of this invention. Even if the packaging material contains athermoplastic layer polluted by impurities, the seal performances canhave the desired strength and the desired liquid tight characteristics.In addition, if the packaging materials are sealed under the liquidsurface of a liquid food, and seal prevention residual substance can beremoved from the surface of the thermoplastic layers, and/or the sealprevention residual substance can be well mixed. Also, if the packaginglaminated material is covered with residual substance of the oxide andthe content, etc., the bad influence associated with such sealprevention impurity can be reduced, and a possible optimum seal can beobtained.

In the seal jaw and counter jaw in the packaging system, the mainfunction of the counter jaw is to apply pressure and the function of thecounter jaw has been recognized to be of low importance compared withthe seal jaw. However, the working efficiency and cost performance areoptimized by decentralizing the function to the seal jaw and the counterjaw. Stagnant content liquid is not formed in the seal zone, andcontents liquid such as juice does not adhere hygienically to the crosssection of a seal zone. Since the seal jaw has a flat operation surface,the generating high frequency magnetic field is uniform and smooth inheat-healing by the high frequency induction heating with the inductorof the seal jaw. Moreover, when heat-healing by ultrasonic heating usingthe horn of a seal jaw, there is no unevenness in a horn surface,uniform heating can be enabled, and a seal which does not have theworn-out crack of a heat-sealing surface, and roughness can be furtherobtained.

The heat-sealing device of this invention and its filling machine areused to manufacture packaging containers filled with liquid food, suchas milk and fruit drinks, from a packaging material web.

1. A heat-sealing device which transversely seals a tube shapedpackaging material filled up with liquid food to form a seal zone of thetube shaped packaging material through softening or melting of plasticmaterial forming a part of the tube shaped packaging material,comprising: a seal jaw and a counter jaw positioned in opposition to oneanother, the seal jaw including means for effecting softening or meltingof the plastic material forming a part of the tube shaped packagingmaterial, the seal jaw and the counter jaw both including an operationsurface that faces and contacts the seal zone during transverse sealingunder a liquid surface of the liquid food, the operation surface of theseal jaw being a flat surface across its entire extent, the seal jawheating the packaging material to soften or melt the plastic material sothat the seal zone is coextensive with the flat operation surface of theseal jaw, the operation surface of the counter jaw being formed with atleast two raised ridges or at least two chevron-shaped elements toremove seal prevention impurity including the liquid food which mayremain in the seal zone, or to mix the seal prevention impurity with thesoftened or melted plastic material.
 2. The heat-sealing device of claim1, wherein the operation surface of the counter jaw is formed as asloped surface.
 3. The heat-sealing device of claim 1, wherein the meansfor effecting softening or melting of the plastic material forming apart of the tube shaped packaging material includes an inductor for highfrequency induction heating.
 4. The heat-sealing device of claim 1,wherein the means for effecting softening or melting of the plasticmaterial forming a part of the tube shaped packaging material includes ahorn for forming the seal zone by ultrasonic heating.
 5. Theheat-sealing device of claim 1, wherein the means for effectingsoftening or melting of the plastic material forming a part of the tubeshaped packaging material includes a resistance body for forming theseal zone by heating.
 6. The heat-sealing device of claim 1, wherein theoperation surface of the counter jaw is formed with the at least tworaised ridges or the at least two chevron-shaped elements to remove sealprevention impurity including the liquid food which may remain in theseal zone, and to mix the seal prevention impurity with the softened ormelted plastic material.
 7. A heat-sealing device which transverselyheat-seals a tube shaped packaging material, formed from a packagingmaterial web and filled up with liquid food, in a seal zone of the tubeshaped packaging material that contains a cutting predetermined zonethrough softening or melting of plastic material forming the packagingmaterial, the heat-sealing device comprising: a seal jaw and a counterjaw; the seal jaw and the counter jaw both including an operationsurface that faces and contacts the seal zone during transverse sealingunder a liquid surface of the liquid food, the operation surface of theseal jaw being a flat surface across its entire extent, the seal jawheating the packaging material to soften or melt the plastic material sothat the seal zone is coextensive with the flat operation surface of theseal jaw, the operation surface of the counter jaw includingremoval/mixture means for removing from the seal zone seal preventionimpurity including the liquid food which may remain in the seal zone, ormixing the seal prevention impurity with the plastic material that hassoftened or melted, the removal/mixture means comprising at least tworaised ridges or at least two chevron-shaped elements on the operationsurface of the counter jaw.
 8. The heat-sealing device of claim 7,wherein the removal/mixture means is a sloped surface forming theoperation surface of the counter jaw.
 9. The heat-sealing device ofclaim 7, including an inductor for high frequency induction heating thatis arranged at the seal jaw, and the packaging material comprises ametal thin layer and a thermoplastic material innermost layer.
 10. Theheat-sealing device of claim 7, including a horn for forming the sealzone by ultrasonic heating that is arranged at the seal jaw, and thepackaging material includes at least a thermoplastic material innermostlayer.
 11. The heat-sealing device of claim 7, including a resistancebody for forming the seal zone by heating that is arranged at the sealjaw, and the packaging material includes at least a thermoplasticmaterial innermost layer.
 12. The heat-sealing device of claim 7,wherein the removal/mixture means removes from the seal zone sealprevention impurity including the liquid food which may remain in theseal zone and mixes the seal prevention impurity with the plasticmaterial that has softened or melted.
 13. A filling machine for formingan advancing packaging material web into a tube shaped packagingmaterial, filling up liquid food in the tube shaped packaging material,and transversely heat-sealing the tube shaped packaging material in aseal zone of the packaging material containing a cutting predeterminedzone through softening or melting of plastic material forming thepackaging material, comprising: a heat-sealing device for forming theseal zone, the heat sealing device comprising a seal jaw and a counterjaw that both include an operation surface facing and contacting theseal zone during transverse sealing under the liquid surface of theliquid food, the operation surface of the seal jaw being a flat surfaceacross its entire extent, the seal jaw heating the packaging material tosoften or melt the plastic material so that the seal zone is coextensivewith the flat operation surface of the seal jaw, the operation surfaceof the counter jaw including removal/mixture means on the operationsurface of the counter jaw for removing from the seal zone sealprevention impurity which may remain in the seal zone, or mixing theseal prevention impurity including the liquid food with the plasticmaterial that has softened or melted, the removal/mixture meanscomprising at least two raised ridges or at least two chevron-shapedelements on the operation surface of the counter jaw.
 14. The fillingmachine of claim 13, wherein the removal/mixture means is a slopedsurface forming the operation surface of the counter jaw.
 15. Thefilling machine of claim 13, including an inductor for high frequencyinduction heating that is arranged at the seal jaw, and the packagingmaterial comprises a metal thin layer and a thermoplastic materialinnermost layer.
 16. The filling machine of claim 13, wherein a horn forforming the seal zone by ultrasonic heating that is arranged at the sealjaw, and the packaging material includes at least a thermoplasticmaterial innermost layer.
 17. The filling machine of claim 13, includinga resistance body for forming the seal zone by heating that is arrangedat the seal jaw, and the packaging material includes at least athermoplastic material innermost layer.
 18. The filling machine of claim13, wherein the removal/mixture means on the operation surface of thecounter jaw removes from the seal zone seal prevention impurity whichmay remain in the seal zone, and mixes the seal prevention impurityincluding the liquid food with the plastic material that has softened ormelted.